Inactivation of indicator microorganisms and biological hazards by standard and/or alternative processing methods in Category 2 and 3 animal by‐products and derived products to be used as organic fertilisers and/or soil improvers

Abstract

The European Commission requested EFSA to assess if different thermal processes achieve a 5 log 10 reduction in Enterococcus faecalis or Salmonella Senftenberg (775W) and (if relevant) a 3 log 10 reduction in thermoresistant viruses (e.g. Parvovirus ) as well as if different chemical processes achieve a 3 log 10 reduction of eggs of Ascaris sp., in eight groups of Category 2 and 3 derived products and animal by‐products (ABP). These included (1) ash derived from incineration, co‐incineration and combustion; (2) glycerine derived from the production of biodiesel and renewable fuels; (3) other materials derived from the production of biodiesel and renewable fuels; (4) hides and skins; (5) wool and hair; (6) feathers and down; (7) pig bristles; and (8) horns, horn products, hooves and hoof products. Data on the presence of viral hazards and on thermal and chemical inactivation of the targeted indicator microorganisms and biological hazards under relevant processing conditions were extracted via extensive literature searches. The evidence was assessed via expert knowledge elicitation. The certainty that the required log 10 reductions in the most resistant indicator microorganisms or biological hazards will be achieved for each of the eight groups of materials mentioned above by the thermal and/or chemical processes was (1) 99–100% for the two processes assessed; (2) 98–100% in Category 2 ABP, at least 90–99% in Category 3 ABP; (3) 90–99% in Category 2 ABP; at least 66–90% in Category 3 ABP; (4) 10–66% and 33–66%; (5) 1–33% and 10–50%; (6) 66–90%; (7) 33–66% and 50–95%; (8) 66–95%, respectively. Data generation on the occurrence and reduction of biological hazards by thermal and/or chemical methods in these materials and on the characterisation of the usage pathways of ABP as organic fertilisers/soil improvers is recommended.

Assessment on the efficacy of methods 2 to 5 and method 7 set out in Commission Regulation (EU) No 142/2011 to inactivate relevant pathogens when producing processed animal protein of porcine origin intended to feed poultry and aquaculture animals

“…Based on the approved parameters provided by the industry, five scenarios of individual time/temperature profiles were selected for the scope of this assessment in order to apply for method 7 the same methodological approach followed for methods 2 to 5. The selected scenarios were: scenario 1–80°C for at least 14 min; scenario 2–95°C for at least 90 min; scenario 3–115°C for at least 56 min; scenario 4–125°C for at least 10 min; scenario 5–133°C for at least 5 min. The level of inactivation of the selected indicators was calculated using the parameters of the Bigelow model fitted to thermal inactivation parameters retrieved for the four indicators from a previous EFSA scientific opinion (EFSA BIOHAZ Panel, 2021) and/or from extensive literature searches. Matrices with different levels of fat and proteins were included in the data modelling. The model to estimate the level of inactivation of relevant pathogens was applied to limited experimental data and built up with certain assumptions that may result in an under‐estimation of the levels of reduction achieved, mostly for methods for which the temperature is above those for which thermal inactivation data are available. Considering the data retrieved from the literature and the model estimates for the four selected indicators, the lowest probability of achieving the target level of inactivation was estimated for the spores of C. perfringens for all methods. The results of the simulation showed a probability of inactivation of at least 5 log 10 of spores of C. perfringens of over 0.99 for methods 2, 3 and 5, in both coincidental and consecutive modes and 0.92 for method 4 in consecutive mode.…”

“…The thermal inactivation parameters (AQ3) of spores of C. perfringens were retrieved through an extensive literature search (ELS), while those of S. Senftenberg and E. faecalis were collated in a previous EFSA scientific opinion (EFSA BIOHAZ Panel, 2021). The thermal inactivation parameters of the relevant viral families were retrieved through an ELS and from a previous EFSA scientific opinion (EFSA BIOHAZ Panel, 2021). Parvoviruses were selected as the most thermal resistant viral hazards for the assessment.…”

“…For data extraction, the papers were screened for evidence of thermal inactivation (D‐values, z‐values, log 10 reductions or any other measurement) following heat treatment with defined temperature/time combinations. The information retrieved through literature search was complemented with thermal inactivation data available for the same viral families in previous EFSA Opinions (EFSA BIOHAZ Panel, 2021 ). The data from the different papers were used to extract D‐values at different temperatures or, when this was not possible due to data limitations (e.g.…”

“…It was also assumed that the survivor curves of the different reference microorganisms presented a linear shape. No shoulder or tailing effects were considered, as the D and z values were obtained from the original studies identified in the extensive literature search for each microorganism and in a previous scientific opinion (EFSA BIOHAZ Panel, 2021 ).…”

“…Data on thermal inactivation of E. faecalis were obtained from Ugwuanyi et al (1999) (digestion waste), S örqvist (2003) (mixed liquid medium), Aguirre et al (2009) (whole milk) and Saucier and Plamondon (2011) (ground beef), as in a previous EFSA scientific opinion (EFSA BIOHAZ Panel, 2021). For E. faecalis, all available thermal inactivation data were used to adjust Equation (2) in order to determine the means and standard errors to model the uncertainty distributions about log 10 D ref and z.…”